The contents of automobiles are beyond your "right" in many states. Your property rights don't cancel out my property rights.
Your property rights should not, in a free country, allow you to bring anything onto my property that I don't want you to bring. You have RKBA, but you don't have it on my property without my consent.
As I mentioned in my first post, some posters are falling into the liberal trap of thinking that corporate property is public property. It isn't, any more than your own driveway is.